Adaptive compression

• US 7,783,781 B1
• Filed: 10/05/2005
• Issued: 08/24/2010
• Est. Priority Date: 08/05/2005
• Status: Active Grant

• Current Assignee: F5 Networks, Inc. (F5 Incorporated)
• Original Assignee: F5 Networks, Inc. (F5 Incorporated)
• Inventors: Mukerji, Arindum, Rothstein, Jesse Abraham, Schmitt, David D.
• Primary Examiner(s): Srivastava; Vivek
• Assistant Examiner(s): Hossain; Tanim
• Application Number:
  US11/243,629
• Time in Patent Office: 1,784 Days
• Field of Search: 709/247, 709/223
• US Class Current: 709/247
• CPC Class Codes: H03M 7/00 Conversion of a code where information is represented by a given sequence or number of digits to a code where the same , similar or subset of information is represented by a different sequence or number of digits
• CPC Class Codes: H03M 7/30 Compression speech analysis-synthesis for redundancy reduction G10L19/00; for image communication H04N; Expansion; Suppression of unnecessary data, e.g. redundancy reduction
• CPC Class Codes: H03M 7/3068 Precoding preceding compression, e.g. Burrows-Wheeler transformation
• CPC Class Codes: H03M 7/4043 Adaptive prefix coding
• CPC Class Codes: H03M 7/6064 Selection of Compressor
• CPC Class Codes: H04L 67/06 specially adapted for file transfer, e.g. file transfer protocol [FTP]
• CPC Class Codes: H04L 69/04 Protocols for data compression, e.g. ROHC

Abstract

A method, system, and apparatus are directed towards compression of content over a network. The content may include content length information, such as within a header. In one embodiment, a portion of the content may be compressed to approximately fill a buffer of a predefined size. If there remains additional uncompressed content, a new content length may be determined based in part on the length of the compressed content and the remaining uncompressed content. The buffered content and the new content length may then be forwarded in response to the request. The remaining uncompressed content may be split into predefined blocks using identity compression. Identity compression may then be applied to the remaining uncompressed content which is then forwarded to a destination in response to the request.

Claims

1. A network device for communicating a file over a network, comprising:

a transceiver to send and receive data over the network; and

a compression component that is programmed to perform actions comprising;

receiving the file;

compressing at least a portion of the file into a buffer using a first compression mode to create a compressed block;

if the compression of at least the portion of the file using the first compression mode results in the file being completely compressed into the buffer, determining an adjusted file length for the file, based, in part, on the size of the compressed block, and sending the compressed block and the adjusted file length to a destination; and

if the compression of at least the portion of the file using the first compression mode results in the file being incompletely compressed into the buffer,

determining an expected file length for the file based, in part, on a remaining portion of the file that is currently uncompressed based on a second compression mode, wherein the first compression mode and the second compression mode are different from each other;

sending the compressed block and the expected file length towards the destination;

compressing the remaining portion of the file into at least one additional compressed block using the second compression mode, and

sending the at least one additional compressed block towards the destination.

2. The network device of claim 1, wherein sending the adjusted file length further comprises, sending a header that includes the adjusted file length, and sending the expected file length comprises sending another header that includes the expected file length.

3. The network device of claim 1, wherein the second compression mode is an identity compression.

4. The network device of claim 1, wherein determining the expected file length further comprises determining the expected file length based on at least one of a size of the compressed block, a size of the remaining portion of the file, a block header, or a size of a compression trailer.

5. The network device of claim 1, wherein determining the expected file length further comprises determining the expected file length based on a size of the compressed block and a size of the remaining portion of the file.

6. The network device of claim 1, wherein the first compression mode uses maximum compression.

7. The network device of claim 1, wherein sending the compressed portion of the file and sending the compressed remaining portion of file further comprises using HTTP to send the compressed block and the additional compressed block.

8. The network device of claim 1, wherein the buffer is a fixed-size.

9. The network device of claim 1, the actions further comprising:

receiving the file from a first network device; and

sending the compressed block to a second network device.

10. A network device for communicating a file over a network, comprising:

a transceiver to send and receive data over the network; and

a compression component that is programmed to perform actions comprising;

receiving the file;

compressing at least a portion of the file into an output buffer;

if the file incompletely compresses into the output buffer;

determining an expected file length based, in part, on a remaining portion of the file that is currently uncompressed based on a compression file format,

sending the compressed portion of the file and the expected file length towards a destination,

encoding the remaining portion of the file into uncompressed blocks as defined by the compression file format, and

sending the encoded remaining portion of file towards the destination; and

otherwise;

determining an adjusted file length for the file based, in part, on the size of the compressed file and sending the compressed file and adjusted file length to the destination.

11. The network device of claim 10, wherein the output buffer is a fixed-size buffer.